The paleontological discovery at Corral Bluffs Open Space in eastern El Paso County made national news last fall when Colorado scientists published the discovery of a trove of fossils in Science magazine. The groundbreaking find helps to fill in gaps in the fossil record and sheds new light on the planet’s recovery and the rise of early mammals after a massive asteroid strike wiped out the dinosaurs 66 million years ago.
Researchers from the Denver Museum of Nature and Science (DMNS) have been searching in Corral Bluffs for the past 30 years, and the site has been of prehistoric interest since the early 1900s, thanks to its Pierre shale, known to preserve fossils of some of the world’s last dinosaurs. While this is the area’s biggest find, it’s only the beginning. “We’ve only started our work at Corral Bluffs,” says Ian Lyson, museum curator at DMNS.
Lyson and Ian Miller, curator of paleobotany and director of Earth and space sciences at DMNS, led the team that discovered thousands of preserved animal and plant fossils.
“The Bluffs were on my radar even as a CC student,” says Ian Miller, who graduated from Colorado College in 1999. Even as an undergrad, Miller and his supervisors were aware that fossils had been found in the area, including an important mammal skull discovered by local science teacher Sharon Milito.“We knew there were a few fossils there, but nothing so significant as to mount a huge effort to study them in great detail,” Miller says.
Miller collected fossil leaves during his internship with the museum and wrote his senior honors thesis on the Corral Bluffs collections. He returned to Corral Bluffs in 2006 after joining the museum staff full time to “collect sparse data,” but didn’t make any breaking discoveries. Then in 2015, Lyson and Miller followed their instincts to the bluffs again—and Lyson had a lightbulb moment. After studying in South Africa, where many fossils were hidden inside rocks called concretions, he began searching for the ugly, egg-shaped rocks at Corral Bluffs. When he found and cracked them open, he literally cracked the case. Inside were skulls of mammals that survived the asteroid strike. The team found four such skulls in one day, then more than a dozen in a week. So far, the researchers have found fossils from at least 16 different mammal species.
Today, the Great Plains east of the Springs are dry, but the newly found fossils show past marine life. “The most common fossils would be bivalves, ammonites and mosasaurs [large marine reptiles] from an ancient seaway that split North America in two, 70-90 million years ago,” Lyson explains. The ancient fossils are still so intact that the researchers can study the animals’ brain size, inner ears, sense of smell, balance, hearing and more.
Lyson and his team are now searching and studying animal and plant fossils for more diverse data surrounding climate changes, the recovery of forests and the rise of mammalian life after the mass extinction event. “Finally, given vertebrate fossils are so rare, with every discovery we will be refining the vertebrate patterns (biostratigraphic, body mass, etc.),” Lyson says. The team hopes to fill small missing gaps in the vertebrate and plant record.
“I have no doubt that our team will continue to work Corral Bluffs for the next few decades,” Lyson says. “And scientists will continue to study this area with new techniques, eyes and ideas for centuries to come.”
See for Yourself
The Corral Bluffs Alliance offers guided hikes of Corral Bluffs Open Space monthly. Info and registration: corralbluffs.org